Acta Prediatr Scand 79: 1237-1 239. 1990
SHORT COMMUNICATION Plasma Levels of B-Endorphin and Substance P in the First Year of Life in Full-Term and Preterm Infants The neuropeptides P-endorphin and substance P are known to have several physiological roles, for example a modulatory effect on respiratory control mechanisms. There are some studies describing the correlation between increased P-endorphin release and perinatal asphyxia or respiratory disturbances in newborn infants (1,2). There are also some results concerning the correlation of altered levels of P-endorphin or substance P and sudden infant death syndrome (3, 4, 5). Our study was designed to determine the plasma concentration pattern of these neuropeptides during the first year of life in full-term and preterm infants. Developmental norms are needed to contrast these levels with those in different disorders. Two groups of infants were investigated: healthy full-term infants (controls) and preterm infants (gestational age < 37 weeks). The age of the infants ranged from -4 (postnatal age was corrected for a gestational age of 40 weeks) to 63 weeks. Investigations were performed after the third week of life. 160
0 140
A
120
E
0
a
0 A A
100
\
x
\
a
2
1
0
0
0
0
0
m
0
u c
2n $ 6 0
20
0 0 -10 - 5
10 15 20 25 50 35 40 corrected oge / weeks Opretenn A controls
0
5
-
45
50
55
----
Fig. I . SPLI in plasma (pg/ml) in the groups of preterm infants (number of patients/investigations:49/132) and full-term infants (controls) (30/41) shown in the first year of life. Regression function for age dependence in preterms: SPLI= 16.41+(0.78xage), r=0.281,p
SHORT COMMUNICATION Plasma Levels of B-Endorphin and Substance P in the First Year of Life in Full-Term and Preterm Infants The neuropeptides P-endorphin and substance P are known to have several physiological roles, for example a modulatory effect on respiratory control mechanisms. There are some studies describing the correlation between increased P-endorphin release and perinatal asphyxia or respiratory disturbances in newborn infants (1,2). There are also some results concerning the correlation of altered levels of P-endorphin or substance P and sudden infant death syndrome (3, 4, 5). Our study was designed to determine the plasma concentration pattern of these neuropeptides during the first year of life in full-term and preterm infants. Developmental norms are needed to contrast these levels with those in different disorders. Two groups of infants were investigated: healthy full-term infants (controls) and preterm infants (gestational age < 37 weeks). The age of the infants ranged from -4 (postnatal age was corrected for a gestational age of 40 weeks) to 63 weeks. Investigations were performed after the third week of life. 160
0 140
A
120
E
0
a
0 A A
100
\
x
\
a
2
1
0
0
0
0
0
m
0
u c
2n $ 6 0
20
0 0 -10 - 5
10 15 20 25 50 35 40 corrected oge / weeks Opretenn A controls
0
5
-
45
50
55
----
Fig. I . SPLI in plasma (pg/ml) in the groups of preterm infants (number of patients/investigations:49/132) and full-term infants (controls) (30/41) shown in the first year of life. Regression function for age dependence in preterms: SPLI= 16.41+(0.78xage), r=0.281,p
